Multiple examples exist for the arrangement of clutches and actuating devices thereof in automatic transmissions. U.S. Pat. No. 6,120,410 shows a clutch arrangement in an automatic transmission in which a part, designed somewhat cup-shaped in transverse section, is constructed as an outer disc carrier. Radially within the outer disc carrier are formed the inner and outer discs of two multi-disc clutches disposed axially adjacent on the same radial height, piston-cylinder arrangements having each one actuating piston for actuation of the two clutches, the same as pressure compensation spaces for a dynamic pressure compensation regarding the actuating force of the actuating pistons.
Also known from this publication is to form a pressure compensation space using one clutch piston and one so-called baffle plate, the same as to situate one recoil spring between the baffle plate and the piston. Lubricant is supplied to the pressure compensation space via a lubricant hole of the outer disc carrier.
Further known from the Applicant's unpublished DE-102 48 172 is an automatic transmission having a multi-disc clutch which has one serve device located within a disc carrier in the form of a piston-cylinder arrangement with dynamic pressure compensation for actuating a clutch. In addition, a planetary gearset, having one planet carrier, belongs to this automatic transmission.
The servo device of this transmission consists of one piston which, together with a suitably designed wall of the disc carrier, forms a pressure space. A pressurization of the pressure space, via a pressure-medium supply hole in the disc carrier, produces an axial displacement of the piston toward the discs after overcoming the recoil force of a spring.
Upon the side of the piston opposite the pressure space, a pressure compensation space is situated by way of a dynamic pressure appearing upon the clutch as a result of the clutch rotation is compensated at least approximately. To this end, the pressure compensation space is filled with a lubricant fed via a hole placed in a hub of the disc carrier. In this known transmission, at the same time, the pressure compensation space, located radially below the clutch discs, is formed by one streamlined spacer disc as an axially stationary baffle plate and by a cup-shaped section of the axially displaceable actuating piston.
Lubricant is supplied to the planetary gears and to the pressure compensation space, via a common lubricant supply situated in the area of the inner diameter of the streamlined spacer disc, and is fed by the already mentioned lubricant supply hole. On the radially inner lubricant inlet in the pressure compensation chamber, the lubricant flow from the lubricant supply hole is divided in two partial flows where one partial flow is guided to the pressure compensation chamber and a second partial flow is guided to a lubricant chamber near the planetary gears.
To obtain the shortest clutch arrangement length, this transmission provides for a streamlined spacer disc, which has axially, stamped corrugations of radial direction distributed over its periphery. The axially-formed, stamped grooves are connected either with a lubricant chamber for lubricating the planetary gears or with the pressure compensation space for the clutch actuating pistons.
Against this background, the invention is based on the problem of introducing a clutch arrangement for an automatic transmission which, with great saving of space, makes possible the supply with a lubricant or coolant of at least one pressure compensation space and of at least one multi-disc clutch possible.
The solution of this problem results form the features of the main claim while advantageous developments and other embodiments can be deduced from the sub-claims.